266 MISSION OF SAN CARLOS. 
retired to rest. The family slept only till two in 
the morning, when they began to converse in their 
hammocks. This custom of being awake four or 
five hours before sunrise Humboldt found to be 
general among the people of Guiana; and, hence, 
when an attempt is made to surprise them, the first 
part of the night is chosen for the purpose. | 
Proceeding down the Rio Negro they passed the 
mouth of the Casiquiare, the river by which a com- 
munication is effected between the former and the 
Orinoco ; and towards evening reached the mission 
of San Carlos del Rio Negro, with the commander 
of which they lodged. The military establishment 
of this frontier post consisted of seventeen soldiers, 
ten of whom were detached for the security of the 
neighbouring stations. The voyage from the mouth 
of the Rio Negro to Grand Para occupying only 
twenty or twenty-five days, it would not have taken 
much more time to have gone down the Amazon 
to the coast of Brazil, than to return by the Casi- 
quiare and Orinoco to that of Caraccas ; but our tra- 
vellers were informed that it was difficult to pass 
from the Spanish to the Portuguese settlements ; — 
and it was well for them that they declined this 
route, for they afterwards learned that instructions 
had been issued to seize and convey them to Lis- 
bon. This project, however, was not countenanced 
by the government at home, who, when informed 
of the zeal of its subaltern agents, gave instant orders 
that the philosophers should not be disturbed in their 
pursuits. | 
Among the Indians of the Rio Negro they found | 
some of those green pebbles known by the name of 
Amazon-stones, and which are worn as amulets. 
a 2 
